Answer:
99% (two-sided) confidence interval for the true average echo duration is
0.87±0.10. (between 0.77 and 0.97 sec)
We are 99% confident that this interval contains the true population mean.
Step-by-step explanation:
Confidence Interval can be calculated using M±ME where
And margin of error (ME) can be calculated using the formula
ME=[tex]\frac{z*s}{\sqrt{N} }[/tex] where
Then ME=[tex]\frac{2.58*0.40}{\sqrt{101} }[/tex]≈0.10
99% (two-sided) confidence interval for the true average echo duration is
0.87±0.10.